Well apparatus and system



p 1957 H.U. GARRETT ET AL 2,304,830

WELL. APPARATUS AND SYSTEM 4 Sheets-Sheet 1 Filed Jan. 8, 1.953

ENRY U. GARRETT CLIFFORD M. PETERS FIG.2

PAP!

INVENTOR. BY fi 7 Z 5 Se t. 3, 1957 H. u. GARRETT ET AL 2,304,830

WELL APPARATUS AND SYSTEM Filed Jan. 8, 1953 I 4 Sheets-Sheet 3 FIG. 7 38a HENRY U. GARRETT CLIFFORD M. PETERS INVENTOR.

Sept. 3, 1957 H. UQGARRETT ETAL 2,804,330

WELL APPARATUS AND SYSTEM 4 Sheets-Sheet 4 f .HENRY U. GARRETT CLIFFORD NLPETERS Filed Jan. 8, 1953 4 INVENTOR. K

FIG.I4,

Elite tats WELL APPARATUS AND SYSTEM Henry U. Garrett and Clifford M. Peters, Houston, Tex., assignors, by mesne assignments, to U. S. Industries, Inc., a corporation of Delaware Application January 8, 1953, Serial No. 330,294

34 Claims. (Cl. 163-233) mon practice to mount the valves upon mandrels which a are connected into and serve as a part of a tubing string. The rnandrels and their associated valves are each spaced apart vertically along the tubing string in accordance with spacing principles well-known to those skilled in the art.

In the past, it has been necessary to pull and rerun the tubing string each time it was desired to change one or more of the gas lift valves. Such changes are necessitated by any one of several reasons. For example, a part of a gas lift valve, such as a bellows, may fail so that the valve becomes difiicult to operate or even totally inoperative. Further, many gas lift valves are equipped with gas injection ports of a size dependent upon the conditions obtaining in the well. Such conditions may change sufiiciently to warrant or demand a change in port size of one or more of the valves. When a pressure charged type of valve is used, a change in available lifting gas pressure often necessitates a change in the charge pressure of the valves. Thus, for these and other reasons,

{CHI F a change in valves or in their operating characteristics is not infrequently found necessary.

As stated above, a change in gas lift valves has heretofore commonly necessitated pulling and re-running the tubing. Inasmuch as such tubing may be several thousand feet in length, the task assumes considerable proportions and results in the expenditure of considerable money and the loss of production time for the well. The magnitude of the cost will perhaps be better understood when it is considered that in most instances a pulling rig must be transported to the well site and set up. Many wells must then be killed with water or mud before the tubing is pulled. The casing-tubing packer must also be broken loose and this can be a difiicult task in wells where the packer has been set for a long period of time. Finally, the tubing must be pulled and while a well-trained crew can pull a thousand feet of tubing per hour, unexpected difficulties or inexperienced personnel often cause this rate to be considerably less. After the tubing has been re-run and the packer set, the well must be unloaded of the water or mud previously injected to kill it. From the above, it will readily be appreciated that the expense of pulling and re-running is one very prominent reason why well operators presently dislike to change gas lift valves once they are installed.

Another reason for this dislike, and one which is of paramount importance in many cases, is that many wells must be killed with water or mud in order to pull the tubing. When the packer is broken loose preparatory to pulling the tubing, the producing formation would be Opened to the surface of the Well through the casing- 2,894,830 Patented Sept. 3, 1957 tubing annulus if water or mud were not pumped into the well to load it with a hydrostatic head preventing flow from the formation into the open well. With this procedure, there is always present the very great danger that such water, and particularly mud when used, will flow into the producing formation and seal it against flow of oil when the well is later unloaded. Further, cave-ins and other formation faults may develop causing a decrease in production so that there results a reworking or even abandonment of the well.

' From the foregoing, it will be readily seen that the substantial expense of changing a gas lift valve arises not so much from the cost of the valve itself, but to a far greater extent from the manipulations necessary to make such change possible. The permanent loss of a single well due to these manipulations may cost the operator as much as hundreds of gas lift valves.

In practicing one aspect of the concept of this invention, it is possible to effectively change from one gas lift valve at any desired level in the well to another valve without pulling and re-running the tubing and it is, therefore, a general object of this invention to make it possible tovastly reduce the likelihood of having to remove from a well a conduit carrying fluid admitting means .for admitting fluid into or out of such conduit.

Thus, groups of fluid admitting means are spaced vertically along a conduit in a well with each group comprising a plurality of flow control valves which have flow characteristics influenced by the pressure of the lifting gas or fluid to be admitted from one conduit in a well to another, such valves respectively being inseries with lateral passages in one conduit and there further being valve means in series with such lateral passages and positively controllable from the surface of the well so that the passages can be selectively opened and closed. In this manner, one or more of the lateral passages of any one group can be opened to permit the flow valve associated therewith to control flow into or out of the conduit and to function with any one or more of the flow valves in the other groups to satisfactorily perform the desired gas lift or fluid injection functions.

Another object of this invention is to provide apparatus and a gas lift system permitting selecting a flow control valve from a group of the same to admit fluid into or 'out of a conduit in a well, the valves of such group being spaced in sufiicient vertical proximity with each other jthat any one of them can cooperate with gas lift valves at a higher or a lower elevation in the well to gas lift .Well fluids therefrom.

Another object is to provide a well apparatus compris- "ing a conduit having a lateral passage therethrough and a connector adapted to mount a flow valve in series with such passage, there also being provided a separate valve means operable to selectively open and close such lateral passage to render the flow valve effective and ineffective to control flow through the passage, said valve means being operable from the surface of the well independently of the flow valve making it possible to arrange two of such conduits as a group in a well such that either can function with flow valves above or below such group to gas lift fluids from the well.

Another object of this invention is to provide a novel valve operator particularly adapted to actuate .suchvalve means through an actuating connection to the surface of the well.

Another object of this invention is to provide a well apparatus upon which can be mounted a plurality of flow control valves that have flow characteristics influenced by the pressure of a fluid to be admitted into or dis charged from the apparatus, there being provided in such apparatus lateral passages through which flow can be controlled by the flow valves, and there also being pr0- of Fig. 3.

vided a valve means independently operable from the flow valves to selectively and alternately blank off the lateral passages, or to blank oif all of them, so that the control offluid flow into or out of such apparatus can be through a preselected lateral passage, thus eliminatingremoving such apparatus from a well to substitute or change a flow valve; l

Another object of this invention is to provide a valve operator adapted to shift a valve means between a plurality of positions in order to positively place it in a predetermined position responsive to control at the surface of a well. I 1

Another object of this invention is to provide a well apparatus with which it is possible to alternate between a plurality of means for admitting gas into a column of liquid at one or more points in a well without the necessity of removing the conduit carrying such gas admitting means from the well.

Another object of this invention is to provide an apparatus and system with which a gas lift valve can be blanked off to prevent any flow therethrough by means operable from the surface of the well without removing the apparatus from the well and Without providing such gas lift valve with special construction. to achieve such alternately place one of a group of gas lift valves in operative connection with a conduit on which they are mounted, there being a plurality of such groups disposed along the length of the conduit in accordance with gas lift principles.

Other objects, advantages and features of this invention will be apparent to one skilled in the art upon the consideration of the Written specification, the appended claims and the attached drawings wherein:

Fig. 1 illustrates a Well having installed therein one embodiment of the apparatus of this invention in accordance with the novel system thereof;

Fig. 2 is an illustration similar to Fig. l but shows another embodiment of the apparatus installed in the well in accordance with the same system as in Fig. 1;

Fig. 3 is a vertical section showing one embodiment of the apparatus of this invention;

Fig. 4 is a view taken on the line 44 of Fig. 3;

Figs. 5 and 6 are further embodiments of the apalong the lines 99, 10-10, 11-11 and 12-12, re-

spectively, of Fig. 8;

Figs. 13 and 14 are views illustrating different operative positions of the operator of Fig. 8 in the apparatus usual well head apparatus 22 provided with gas inlets 23. Conduit 21 discharges through the well head as sembly via connection 24 and can be connected with the usual slush pits, storage batteries, etc., in a manner well-known to those skilled in the art. A packer 29 is disposed between tubing 21 and casing 20 at a lower level in the well in accordance with conventional gas lift practices. I

As illustrated in Fig.1, there are provided a plurality of mandrels 25, 26, 27 and 28 spaced at appropriate 'bly is lowered therethrough.

levels within the well in accordance with gas lift principles, as will be discussed more fully below. Each of these mandrels carry a plurality of conventional gas lift valves 30. Such valves can be of the differential, pressure charged, constant flow, or any other type known to those skilled in the art, which are adapted to admit lifting gas into tubing 21 in accordance with gas lift practices.

In Fig. 2, gas lift valves 39 are shown mounted on separate mandrels 25a, 25b, 26a, etc. Such mandrels may be directly connected together as are mandrels 25a and 251) or separated by a length of tubing as are mandrels 27a and 2712 provided only that the gas lift valves are arranged in groups spaced vertically according to gas lift principles with a group in each gas injection zone as discussed below. For the sake of illustration, four such zones are illustrated and are designated as A, B, C and D, it being understood that normally there will be several hundred feet of tubing between each zone as indicated by the broken sections in Figspl and 2. Before discussing the principles of gas lift spacing as applicable to this invention, the illustrated embodiments of the apparatus will be described in detail.

Referring now to Fig. 3, there is illustrated in detail one of the mandrels shown in Fig. l. The mandrel can comprise a body having a longitudinal flow passage therethrough and including sub 31 and sub 32, each having threaded joints as its outer end permitting the mandrel to be made up in the tubing string as a part thereof. Connecting between the interior and exterior ofthe mandrel are a plurality of lateral passages 33 and 34 through which gas can flow from the casing into the tubing for gas lift purposes. The inner ends of such passages include circumferential grooves 33a and 34a, respectively. The mandrel carries a connector associated with the lateral passages for securing a flow valve in series with the lateral passages to control flow therethrough. As illustrated in Fig. 3, such connector comprises threaded portion 35 of the lateral passages. It will be noted that the lateral passages are disposed in shoulders 36 and 37, respectively, in such a manner that gas lift valve 30 can be connected so as to lie parallel to the mandrel and to thereby not only provide a compact assembly readily insertable through the well casing but one in which shoulders 36 and 37 act as guards to prevent the gas lift valves from rubbing against the casing as the assem- Similar guards can be provided above the gas lift valves to augment the pro tection alforded these valves and to provide a support therefor, if desired.

Slidably mounted on the mandrel is a valve means movable to selectively open and close the lateral passages. As

terior and exterior of the sleeve so that when such ports are aligned or in register with one of lateral passages 33 or 34, gas can flow through such lateral passage into the interior of the mandrel.

Seal means are provided between the sleeve and mandrel to prevent flow between the sleeve and mandrel from a lateral passage when the imperforate portion of the sleeve is disposed across such passage. These seal means can comprise seal rings, such as O-rings 41, 42 and 43 carried .by the mandrel in suitable grooves and disposed circumferentially around the sleeve.

it will be noted that one of such rings is spaced to one side and another ring to the other side of the inner end of each of the lateral passages. With the sleeve in the position shown in Fig. 3,

,lateral passage 33 is effectively sealed from communication between the interior and exterior of the mandrel, where- 5 as lateral passage 34,is in communication with the interior of the mandrel;

Sleeve or valve member-38 is-movable between aplurality ofpositions to selectively and alternately open and close each of lateral passages 33 and 34 orto close both of them. Thus, with the structure illustrated in Fig. 3, the sleeve is shown in one position suchthat later-a1 passage 34 is placedin communication with the interior of the mandrel while-lateral passage 33 is bl'ocked'fromsuch communication. Upon moving the'sleeve upwardly to another position where radial ports 40 are in register with lateral passage 33, the latter is then placedin communication with the interior of the mandrel while lateral passage-34 is blocked by the imperforate portion of the sleeve disposed below. ports 40. Upon shifting the sleeve still further upward in the apparatus illustrated in Fig. 3 to another position, radial ports 40 are brought above O-ring 41 and the i'mperforate portion of the sleeve below the radial ports blocks flow throughboth lateral passages 33 and 34. Thus, the sleeve is shiftable among three positions.

Detent means carried by the sleeve and mandrel are provided for releasably securing sleeve-38in at least one and preferably all of such positions; The detent' means can comprise a split snap ring 44 disposed in a circumferential groove 45 in the sleeve; This ring is resilient and of such size that it will maintain a frictional contact with the interior wall of the mandrel and expand into grooves 46, 47" and 48- so as to cooperate therewith--- to complete the detent means. These grooves are spaced. longitudinally along the mandrel a; distance apartsuch that when snap ring 44- engages any groove, sleeve. 38 will be releasably' secured in the desired position as: dis: cussed above.

Stop parts areprovidedbetweenthe sleeve andmandrel for limiting movement of the sleeve. to be between the various of its positions and to prevent movement thereof beyond the extreme ones of such positions: Such stop parts can comprise shoulders 49 and 51' on, the endsof the sleeve adapted to respectively engage shoulder 50'on the lower end of sub 32 and shoulder 52: on lower' sub 31. With this construction, it will be evident thatsleeve. 38? is prevented from moving. downward in the apparatus illustrated in Fig. 3 after radial ports 40, have been brought into proper register with lateral passage. 34; Also, the sleeve is prevented from moving upward past the position it occupies when snap ring 44 engagesgroove 48 so that imperforateportion. 39 is properly'spaced across both of the lateral passages. While: sleeve 38,- is illustrated in Fig. 3' as having radial-portsi40 sodisposed that they are in register with one of lateral passages34 and. 33 with the sleeve in the lowermost: two of its three positions, it will be apparent that the longitudinal location of radial ports 46 in the sleeve" can be varied. For

. example, the ports couldbe situated such that the-uppermost two of the three positions ofthe sleeve are those in: which the; radial ports are in register with the lateral passages. a

In Fig. 7, there is illustrated an apparatusparticularly adapted to be made up as a part. of a tubing string in the manner illustrated in Fig. 2. Such apparatus includes many elements similar in construction and function to those in Fig. 3 and these common parts have'beengiven the same reference character to indicate this similarity. However, a single lateral passage 33:: is provided in shoulder 36a. Sleeve 38a is similarly constructed to sleeve 38 of Fig. 3 but is a two-position sleeve movable to bring radial ports or slots 40a into and out of register with passage 33:: and to bring imperforate portion 390 of the sleeve across the lateral passage with the sleeve in its upper position with. the apparatus disposed asillustrated. The detentmeans for releasably securing the sleeve in at least one of its.two-positions, and preferably both, comprises split ring 44a releasably engageable with grooves 47a and 48a. It will be noted. that. with this O ring;

position sleeve, stop ports 49a, 50, 51a and 52 cooperate to-positivelypreventthesleeve-from moving beyond'either of its positions so-that its movement into one position from another is always positively stopped irrespective of the :d'etent means. With the construction of Fig. 7', the lateral passage is alternately opened and closed and by grouping two of the mandrelstogether as shown in Fig. 2, the same ultimate function for gas lift purposes" can be ob taineds' as with the apparatus of Fig. 3 installed as illustrated' in Fig. 1 However, the apparatus of Fig. 3- is somewhat simpler to. manipulate sinceitrequires but a single engagement ofan operator withsleeve 38? in order to switch-flow valves or to close all of'them whereas two or more sleeves'must be moved to obtain thesame effect with theapparatus ofFig. 7. On the other hand, the apparatus of Fig; 7 permits-somewhat more flexibility of installation of the flowvalves in that they can bespaced vertically apart to any desired extent simply by varying the lengthof tubing therebetween whereas increasing the spacingbetween the flow valves of Fig. 3 requires lengthening' of the mandrel which has an obvious limitation.

As willbe seenin Figs. 3-and7, slots 40 (Fig. 3) and slots-40a (-Fig. 7) in therespectivesleeves have terminal portions 40btaper-ing divergently from each other and outwardly toward the outer wall ofthe sleeve. 'I hese terminal portions extend-tin a direction transverse to the circumferential axes of O-rings 41 and 42 (Fig. 3) and of O-ring 41a (Fig. 7) Then as the ports with these terminalportionsmove past one of the O-rings, any pressure differential across the O-ringisequalized without the O-ring being protruded into the port by the pressure differential. This will prevent pinching ofthe From the foregoing description, it will be apparent that it isnecessary to move sleeves 38 and- 38a in the mandrel or tubing in order to selectively open and close the lateral passages. In accordance with one aspect of this invention, there is provided a valve operator for performing this function, such operator being adapted to be situated adjacent the valve means or sleeve and having an actuating connection with the earths surface. The operator so situated is operable through the actuating connection to'actuate and move the valve means to selectively and alternately open and close the lateral passages, or to close all of them. The actuating connection with the earths surface is preferably a wire line of the type well known to those skilled in the art; While such valve operator can be of any type adapted to perform this function, it is preferred to employ the novel operator illustrated in Figs. 8 through 12.

Referring to these figures, there is shown a body 55 having a connector 56 at one of its ends adapted to be connected to a wire line for manipulation of the operator. The other end of the operator can be closed by a suitable weighting point 57 which also serves as a guideto prevent the operator from catching on tubing joints as" it is loweredin the well. Engaging fingers 58' and 59 are carried by the body for movement of abutment surfaces 58a and 59a outwardly of the body for engagement with one of sleeves 38 or- 38:: as will be presently described; Thus, finger 58, which is closer to connector 56, can be pivotally mounted in the body by pivot pin 60 sothat abutment surface 58a can be pivoted outwardly of the body while finger 59 is similarly pivoted but bya shear pin 61 forming a shearable connection between the body and finger 59. A means or connection is provided between the two fingers to maintain finger 58 retracted until pin 61 is sheared and then to pivot it outwardly; Such connection also biases finger 59 outwardly at all times prior to shearing the pin. This connection can comprise a member 62 slidably mounted in the, body upon a pin 63 passing through a slot 64 in the member and urged toward finger 59 by spring 65; Member 62 has a portion or end 62min engagement with av notch cut in finger 59 so that the member can apply a force to -the finger at a point laterally oft-set from shear pin 61, that is, at a point laterally intermediate shear pin 61 and abutment surface 594:. In this manner, the downward urging of member 62 by spring 65 in turn urges finger 59 outwardly but, upon application of a force tending to retract the finger, the member is also retracted against the force of spring 65. As a result, finger .59 is constantly urged outwardly of body 55. Stop parts are provided between the member and finger 59 to limit the outward movement of the finger and can comprise opposing surfaces 621) and 5941 on the member and finger, respectively. Thus, as the operator is lowered into the well and encounters an obstruction, finger 59 .pivots inwardly to permit the operator to pass such obstruction. It will be noted that even with finger 59 fully retracted into body 55, and 62a of member 62 is still outwardly off-set from pivot pin 61 so as to move the finger outwardly upon removal of the obstruction.

The opposite end 620 of member 62 is provided with an abutment surface 62d engageablewith a corresponding and parallel abutment surface on finger 58 to maintain the finger substantially-retracted within housing 55 prior to shearing pin 61. A relatively weak spring 66 isprovided between member 62 and an ear 67 on finger 58 to pivot the latter outwardly upon substantial movement of member 62 away from the finger as will occur when pin 61 is sheared.

Referring now to the operation of this operator, it .can be connected to a wire line and lowered through the well tubing until it reaches a depth somewhat below the valve means or sleeve to be operated. During such lowering, finger 59 is continually biased outwardly but is free to move inwardly upon encountering an obstruction. After the operator has been lowered below the particular sleeve to be moved, it is moved upwardly so that abutment surface 59a can engage the lower end of the sleeve as shown in Fig. 14. If the sleeve is in one of its lower positions, continued upward movement of the operator raises the sleeve until stop parts 49 and 50 of sleeve 38, or the corresponding stop parts 49a and 50 of sleeve 38a, are in engagement. A further and increased upward pull on the operator will cause pin 61 to shear thereby permitting finger 59 to drop into a cavity 68 in body 55 and member 62 to move away from finger 58. This movement of member 62 pivots finger 58 outwardly and the operator can be lowered until abutment surface 58a engages one of surfaces 49 or 49a on one of the two sleeves. Continued lowering of the operator will move the sleeve downwardly in the mandrel to one of its predetermined positions as discussed above.

With the embodiment shown in Fig. 3, a preferred method of operation is to position sleeve 38 at an intermediate position with snap ring 44 engaging groove 47 when the mandrel is made up in the tubing string. This permits lateral passage 33 to be open to the tubing. If it is desired to close off both of the lateral passages, the operator is lowered through the sleeve and then raised until the latter engages stop part 50. The operator is then removed from the well by shearing pin 61. On the other hand, if it is desired to move the sleeve to open lateral passage 34, the operator can be employed asabove to raise the sleeve until stop parts 49 and 50 are in engagement and then lowered to bring the sleeve to its lowermost position with stop parts 51 and S2 in engagement. This procedure eliminates all doubt as to the position of the sleeve inasmuch as the positive stop parts at each end of the sleeve and mandrel permit positive placement of the sleeve. When the sleeve 38a of Fig. 7 is employed, it can be moved upwardly to blank off lateral passage 33:: by using finger 59 only. If it is desired to move the sleeve downwardly, the operator is lowered therethrough and finger 59 sheared out of position after which finger 58 can be employed to 'move the sleeve downwardly. e

standpoint, as close together as desired.

As illustrated in Figs. 1, 2, 3 and 7, a flow valve of the gas lift type is employed in conjunction with each of the lateral passages. Such flow valves can be of any type known to those skilled in the art which are adapted to control flow of lifting fluid through the lateral passages and which have their flow characteristicsinfluenced by the pressure of the lifting gas to be injected. However, in some instances, it is desirable to employ orifice plugs to control flow of lifting fluid into the tubing. Such an orifice plug is illustrated at 70 in Figs. 5 and 6 and the term flow valve as used in the specification and claims is intended to include within its scope an orifice of the general type illustrated in these figures. Such an orifice plug can be used in combination With a gas lift valve 30 as shown in Fig. 5 or two such orifice plugs can be used together as shown inFig. 6. The structure of Figs. 5 and 6 is particularly arranged to have such orifices screwed into connectors carried by the mandrel so that flow can take place through the orifices into the lateral passages and thence into the interior of the mandrel via the radial ports in the sleeve. However, if desired, the orifice plugs can be constructed of a size ast-o be screwed directly into theconnectors 35 of Figs. 3 and 7 so that a single type of mandrel can be employed for both gas lift valves and orifice plugs. Since the operation of the sleeve is similar with the orifice plugs as with the gas lift valves, further description will not be given herein.

As illustrated in Fig. 1, there are a plurality of lateral passages connecting between the interior and exterior of the tubing with the passages being arranged in vertically spaced apart groups of at least two passages per group. Each passage in any group is spaced, relative to each passage in any other group, in accordance with gas lift spacing principles so that any selected passage in each group can be opened to produce a well according to gas lift practices well known to those skilled in the art. Stated in another manner, there is a first passage in each group which is vertically spaced apart with respect to a first passage in each other group in accordance with gas lift spacing principles. There is also provided a second passage in one group vertically spaced apart relative to a second passage in another group, the second passage in each of such groups being in sufficient vertical proximity to the first passage in the same group that either the first or the second passages of the same group can be opened to admit gas to produce a well according to gas lift principles in cooperation with other passages in the tubing. As is well known to those skilled in the art, a plurality of gas lift valves can be spaced along a tubing with a single one of such valves each in what may be termed a zone as indicated by the letters A, B, C and D in Figs. 1 and 2. The lower limit of each such zone, or alternatively, the maximum spacing between the valves or the upper valve and the well surface, is determined by operating variables and has a definite fixed location dependent upon the conditions existing at any given time in a well. In other words, there is a mathematically determinable limit to the maximum distance that the gas lift or flow valves can be spaced apart and spacing beyond such limit will render the gas lift system inoperative to perform its intended function. On the other hand, the upper limit of each zone is principally determined by economic factors, that is, the gas lift valves can be spaced, from an operative However, too close spacing increases the cost of installation of the gas lift system due to the 'cost of additional valves not necessary to satisfactorily perform the operation. Accordingly, the upper limit of each zone is usually set to be as close to the lower limit of each zone as is possible and yet provide an adequate safety factor which takes into account the operating characteristics of the particular Valve to be installed in the well, the probable accuracy of the measurement of well conditions, the probable change in such conditions after production has taken place for a period of time, and other factors well known to those skilled in the art. Suflice it to say that such zones are ordinarily considered to be relatively narrow compared to the total depth of the well and each are separated from others or the topmost from the earths surface by a distance which may be several hundred feet in length.

Io-further discuss these gas lift spacing principles, it will be recognized that in the usual case after the tubing and packer have been set and, if desired, the well washed, it; will. be necessary to remove fluid trapped between the tubing and casing above the packer before the Well can be produced. This is done by applying gas pressure to casing-tubing annulus and U-tubing such liquid out of the well through thetubing. During this operation, all valves below the surface of the liquid will normally be open and the application of gas pressure to the liquid in the casing-tubing annulus forces it to pass through these valves and rise in the tubing to the surface of the well. Thus, the topmost valve must be spaced a distance from the surface of the well not greater than the sum of the length of a column of well fluid being lifted which will exert a pressure equal to the available gas pressure at such valve plus the length of tubing above such a column of well fluid which is free from well liquids. Expressed as a formula, the first valve from the surface of the well should be located a distance not greater than that equal to the available lifting gas pressure minus the tubing pressure at the surface, if any, divided by the static gradient of fluid in the tubing. This static gradient is equivalent to the pressure in pounds per square inch exerted by a one foot column of the Well fluid. The gas and surface tubing pressures in this formula are expressed in pounds per square inch. Of course, if the liquid level of the Well in question is deeper than the spacing indicated by the above formula for the topmost valve, it is then possible to divide the spacing indicated by this formula by the ratio of the annular area of the casing to that of the tubing and add the resulting figure to the actual depth of liquid level. The resulting sum is equal to the distance for spacing the topmost valve from the surface. Of course, if gas is being injected through the tubing into the casing, the above area ratio is considered in reverse.

For spacing lower valves in the tubing, the maximum spacing in feet is given by considerations similar to those discussed above with regard to the topmost valve. Expressed as a formula, the spacing between lower valves equals the available lifting gas pressure minus the pressure in the tubing at the valve immediately above the one to be spaced divided by the static gradient of well fluid in the tubing between the valves.

While the above formulas indicate the maximum spacing of gas lift valves from the surface and between each other, a spacing somewhat less than this is ordinarily usedin order to provide not only a safety factor but also to provide an available differential in pressure between the lifting gas and maximum tubing pressure at a valve so'that the desired quantity of gas will flow through the valve in a predetermined length of time. For a detailed discussion of gas lift valve spacing principles and spacing formulastaking into account this safety factor and differential, as commonly used in the art, reference is made to the 18th (1951) edition of The Composite Catalog of Oil Field and Pipeline Equipment, pages 1817 through 1867. While such formulas are well known to those skilled in the art, the discussion contained in the above publication is incorporated by reference in this specification to assure adequate disclosure. It should be noted that the static gradient commonly used for oil is 0.4 but a static gradient of 0.5 is often used to assure that the installation will handle heavy salt water with ease. Al though a drilling mud is ordinarily flushed from the well by U-tubing it out with water before the packer is set, in some instances it might be lifted out of the well through the use of gas lift valves and in such case, the static gra- 10 dient would have to be made sufliciently large tents into account the heavier weight of the drilling mud.

Referring now again to Figs. 1 and 2, it is in accordance with the concept of this invention that each of the gas lift valves and their lateral passages in zone A are spaced from the surface of the well a distance no greater than that indicated by the maximum distance spacing prin ciples and formulas set out above. In practice, it is preferred that each of these valves and lateral passages be spaced a distance from the well surface equal substantially to that calculated by the formulas appearing in the above noted publication. In this manner, either of the lateral passages can be opened into the tubing to dump the well. It will be understood that one of these valves can be situated above the other as shown in Fig. 2 as long as the lowermost valve is not spaced, beyond the distance indicated by the above maximum spacing formulas. The lateral passages in zone B are each spaced from the uppermost of the lateral. passages in zone A a distance not greater than that indicated by the maximum distance spacing formula above and preferably at a spacing indicated by the formulas of the publication. Then, as long as the other lateral passages in zone B are above the thusly spaced lower lateral passage therein, any of them will always function with any of the lateral passages in zone A in accordance with gas lift practices. The lateral passages in zones C and D are spaced in a similar manner with respect to the lateral passages in zones B and C, respectively.

While much of the above discussion has been directed to apparatus wherein the lifting gas is passed through the casing-tubing annulus and then injected into the tubing, it is contemplated that this flow can be reversed with the gas passing down through the tubing and then injected into the casing-tubing annulus by suitable rearrangement of the structure. Also, while four gas lift zones are shown in Figs. 1 and 2, it will be understood that some wells can be produced with valves in a single zone Whereas deeper wells may require as many as twenty or more zones.

From the foregoing, it will be seen that this invene tion is one well adapted to attain all of the ends and objects hereinabove set forth, together with other ad vantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

1. Anapparatus useful in well operations comprising a mandrel adapted to be connected as a part of a string of well conduit, a plurality of adjacent passages connecting between the interior and exterior of the mandrel, a connector carried by the mandrel and situated with respect to one of said passages to secure a flow valve in series with such passage, and separate valve means carried by the mandrel and selectively movable to open at least one of said passages while closing at least one other of said passages.

2. The apparatus of claim 1 in combination With a valve operator for moving said valve means and an actus ating connection to the operator permitting actuation thereof from a point remote from the mandrel.

3. An apparatus useful in well operations comprising a mandrel adapted to be connected as a part of a string of well conduit, a plurality of adjacent passages extending laterally through a side wall of the mandrel and con:

necting between the interior and exterior of the mandrel, a connector carried by the mandrel and situated with respect to one of said passages to secure a flow valve in series with such passage, a separate valve member slidably mounted on said mandrel and movable between a plurality of positions to selectively open and close said passages, and releasable detent means between the mandrel and said valve member releasably securing said valve member in at least one of said positions.

' 4. The apparatus of claim 3 in combination with mutually engageable stop parts carried by the mandrel and valve member preventing movement of the latter beyond the two farthest spaced apart positions.

5. An apparatus useful in well operations comprising a mandrel adapted to be connected as a part of a string of well conduit and having a fluid passageway therethrough, a plurality of adjacent passages extending through a side wall of said mandrel and connecting between the interior and exterior of the mandrel, a sleeve slidably mounted within the mandrel passageway, said sleeve including an imperforate portion extending With said sleeve in a first position across all of said adjacent passages to block flow therethrough, said sleeve being movable from said first position through a plurality of other positions to open at least one of said adjacent pas- :sages to said passageway at each of said other positions, and a connector situated with respect to at least one of said passages to secure a flow valve in series with such passage.

6. The apparatus of claim 5 in combination with a re leasable detent means between said mandrel and said sleeve for releasably securing said sleeve in at least one of said positions. 7. The apparatus of claim 6 in combination with mutually engageable stop parts carried by the mandrel and sleeve and preventing movement of the sleeve beyond the two farthest spaced apart of said positions.

8. An apparatus useful in Well operations comprising a mandrel adapted to be connected as a part of a string of well conduit and having a fluid passageway there- 'through, a pair of passages extending through a side Wall of said mandrel and connecting between the interior and exterior of the mandrel, said passages being adjacent each other but spaced apart along the length of said mandrel, said passages having walls at their outer ends provided with threads for connecting a flow valve in series with said passages to control flow therethrough, a sleeve slidably mounted in said mandrel passageway and provided with a plurality of radial ports intermediate its ends, said sleeve being movable longitudinally in said mandrel between two positions to selectively place said radial ports in communication with one of said passages and to a third position where the radial ports are out of such communication with both of said passages, said sleeve having an imperforate portion longitudinally spaced from said radial ports so as to extend across the passage out of communication with said ports with the sleeve in one of said two positions and to extend across both said passages with the sleeve in said third position, detent means between the sleeve and mandrel releasably securing the sleeve in a selected one of its three positions, and mutually engageable stop parts carried by the mandrel and sleeve preventing movement of the sleeve beyond the two positions of the sleeve longitudinally spaced farthest apart.

9. An apparatus useful in well operations comprising a mandrel adapted to be connected as a part of a string of well conduit, a passage through a side wall of the mandrel and connecting between the interior and exterior of the mandrel, a fiow valve support part carried by the mandrel and situated for securing a flow valve in series with the passage to control flow through the latter, valve means also in series with said passage and separate from said flow valve and carried by the mandrel and movable to open and close said passage and including a part engageable by a wire line tool for so moving the valve means, and cooperating stop parts carried by the valve means and mandrel limiting movement of the valve means to be between open passage and closed passage positions.

10. An apparatus useful in well operations comprising a mandrel adapted to be connected as a part of a string of well conduit and having a fluid passageway therethrough, a passage through a side wall of said mandrel and connecting between the interior and exterior of the mandrel, a sleeve having an imperforate portion, said sleeve being slidably mounted within the mandrel and movable to a first position placing said passage in fluid communication with said passageway and to a second position to situate said imperforate portion of the sleeve across said passage to block flow therethrough, seal means between the sleeve and mandrel operable with the sleeve in said second position to provide a seal preventing flow between the sleeve and mandrel from said passage, detent means carried by the sleeve and mandrel for releasably securing said sleeve in said first and second positions, and a connector at the end of the passage exterior of the mandrel for securing a flow valve in series with the passage to control flow therethrough. V

11. The apparatus of claim 10 wherein said sleeve is provided with radial ports longitudinally spaced from said imperforate portion and situated to place the passage in fluid communication with said passageway with the sleeve in said first position.

12. The apparatus of claim 11 wherein said seal means include two seal rings carried by the mandrel and disposed circumferentially around the sleeve with one ring spaced to one side and the other ring to the other side of the inner end of said passage.

13. In a well apparatus having a well conduit with a plurality of adjacent passages each extending through a side wall of said conduit and each connecting between the interior and exterior of the conduit, valve means carried by the conduit and controlling fluid flow through said passages, respectively, a valve operator adapted to be situated adjacent said valve means and having an actuating connection with the earths surface, said operator so situated being operable through said connection to actuate said valve means to selectively and alternately open one of said passages while closing another of said passages, and a connector situated with respect to at least one of said passages to secure a flow valve in series with such passage.

14. In a well apparatus having a well conduit with a plurality of adjacent passages each extending through a side wall of said conduit and each connecting between the interior and exterior of the conduit, valve means carried by the conduit and including a part movable between first and second predetermined positions, said part upon moving to said first position opening one passage while closing another passage and, upon moving to said second position, opening said another passage and closing said one passage, and a valve operator releasably engageable with said part and having an actuating connection with the earths surface, said actuator when so engaged with said part being operable through said connection to move said part.

15. In a well having a conduit therein with a plurality of passages extending through a side wall of said conduit and each connecting between the interior and exterior of the conduit, said passages being arranged in vertically spaced apart groups of at least two passages per group with each passage in any group being spaced, relative to each passage in any other group, in accordance with gas lift spacing principles so that a selected passage in each group can be opened to produce a well according to gas lift practices, and valve means for each group of passages movable to selectively open and close the passages of such group. 7

16. In a well having a conduit therein with a plurality of vertically spaced apart groups of passages extending agso igsao lift spacing principles, a second assagsirr said ohegroupalso being vertically spaced apartrelative to asecond passage in said another group,- are second passage in each of such' groups being in-sufiicient-vertical proximity to the first passage in the same groupthateither of the first and second'pas'sages" of the same group can be opened to admit gas to produce a well according to gas lift practices, a plurality of fiow'valves each connected in series with one of said passagesto control flow therethrough responsive to pressure ofa lifting gas, and separate valve means on said conduit movable to selectively open and close thefirst and second" passages of each group.

17. In a well having a conduit therein witha plurality of first passages extending through a side wall of said conduit and connecting between the interior and exterior of said conduit, said passages beingvertically spaced apart in accordance with gas lift spacing principles, a second passage extending through a side wall of said conduit and connecting between the interior and exterior of said conduit and grouped in suifi'ci'en't vertical proximity to one of said first passages that either" of the passages in said group can be opened to produce] a well according to gas lift practices in cooperation with other first pas sages outside said group, and valve means on said conduit movable to selectively and alternately open and close the passages of said group. 7

18. The apparatus of claim 17 in combination with fiow valves connected to each of said first passages and said second passage, said flow valves having their flow characteristics controlled by the pressure of a lifting gas.

19. The apparatus of claim" 17 wherein'the said valve means comprises a sleeve slidably mounted in said' con: duit and movable between first and second positions to alternately open said first and second passages of said group.

20. The apparatus of claim 19 in combination with mutually engageable stop parts carried by the sleeve and conduit preventing movement of said sleeve in one direction when in one of said positions,

21. In a well apparatus having a well fluid eduction conduit and a gas injection conduit with a plurality of vertically spaced apart groups of passages extending through a side wall of one of said conduits and connecting between the interiors of the two conduits, a flow valve connected in series with eachpassage to control fluid flow therethrough, separate valve means for each group of passages and including a valve member carried by one of said conduits movable to selectively open one passage while closing another passage of the group with which it is associated, each of the individual passages of one group being spaced from the surface of the well a distance not greater than the sum of the length of a column of the well fluid to be lifted which will exert a pressure equal to the available gas pressure in the gas injection conduit at the individual passages of said one group plus the length of the eduction conduit above such a column which is free from well liquids and each of the individual passages of a group lower in the well than said one group being spaced from each of the individual passages of said one group a distance not greater than that length of a column of the well fluid to be lifted which will exert a pressure equal to the available gas pressure in the gas injection conduit at the individual passages of said lower group minus the pressure in the liquid eduction conduit at said individual passages of said one group.

22. A valve operator adapted to be manipulated in a well bore by a wire line which comprises, in combination, a body, a first engaging finger having an abutment surface and carried by the body for movement outwardly therefrom to present said abutment surface for engage- T4 ment' with a valve member to be operated, a second en'- gaging finger, ashearab'le connection betweenzsaid' body and said second finger mounting the lattert'opresentan abutment surface outwardly of' said body; and aconnection means between said two fingers moving said first finger outwardly upon shearing. said connection. of said second finger.

23'. A valve operator adapted to be manipulated in a well boreby a wire line which comprises, incombination, a body, first and secondenga'ging fingers each hav ing an abutment surface and being pivotally mounted on said body to swing the abutment surface on each fi'n'ger outwardly of'the body, the'pivotalmounting of said sec ond finger comprising a shea'r pin,- and a connection between the fingers moving said first finger outwardly upon shearing said pin and biasing said second finger outwardly before said pin is sheared.

24'. The'operat'or'of claim 23 wherein saidconnection comprises a member sli'dable in said body and having one portion in engagement withthesecond' finger to urge it about said pin outwardly ofsaid body upon movement of the member toward the second-finger and'another portion engaging said firstfinger preventing its outward pivoting beforesaid pin is sheared, meanslbiasing said member away from the first finger anda linkage" between the member and first finger pivoting the'lat'ter outwardly upon shearing ofsaid pin and movement of said member away'froni said first finger. I

25'. The operator of claim 23 wherein said body is tonne-d with acavity below said' second finger to receive the same upon shearing of said pin. I

26. The operator of claim 23* incomb'ination with a connector carried by said body and adapted to be connected to a wire line; said first finger being disposed nearer the connector than said second finger.

27; A tool adapted to be positioned in a well tubing by a wire line cornprisir'rg a dog carried by the tool for movement between extended and retracted positions and having a portion engageable when the dog is in extended position with an upwardly facing shoulder carried by the well tubing to support the tool in the tubing, means bias= ing the dog to extended: position, .andnieans for holding the dog in retracted positionagainst' force exertedby said biasing. means while the tool is'being lowered into the tubing and then operable to release the dog for movement to an extended position including a finger carried by the tool and biased to an extendedposition so thefinger' can slide along the tubing while the tool is being lowered thereinto and then engageable with a downwardly facing shoulder carried by the tubing upon upward movement of the tool, said tool having a part connectible to the wire line and movable relative to the finger to engage and retract the same, a connection between the finger and part resisting such relative movement but releasable upon the finger engaging said downwardly facing shoulder and an upward pull being exerted on the wire line, and a member engaging said dog to hold it in retracted position and movable to release the dog responsive to movement of said part relative to said finger.

28. A tool adapted to be positioned in a Well tubing by a wire line comprising an extendable dog carried by the tool for engagement with an upwardly facing shoulder carried by the tubing; means releasably holding the dog in retracted position while the tool is being lowered to a position in the tubing; and means for releasing said dog for movement to an extended position including a retractible finger carried by the tool in extended position to slide along the tubing while the tool is being lowered thereinto and then engageable with the tubing upon upward movement of the tool in the tubing, and means for retracting the finger upon an upward pull on the tool While the finger is engaged with said tubing and for causing said holding means to release said dog for movement to an extended position.

29. A tool adapted to be positioned in a well tubing by a wire line comprising first and second extensible and retractible dogs carried by the tool and each biased to extended position for respective engagement with upwardly and downwardly facing shoulders carried by the tubing, a connection between the dogs releasably holding the first dog in retracted position while the second dog is in extended position so the tool can be lowered in the tubing with the second dog sliding along a wall of the tubing and then raised to. engage the second dog with said downwardly facing shoulder, and means for retracting the second dog and causing said connection to release the first dog responsive to an upward pull on the wire line with the second dog engaging said downwardly facing shoulder whereby the first dog can be engaged with said upwardly facing shoulder.

30. The tool of claim 29 wherein said tool includes a part connectible with the wire line and movable relative to the second dog to retract the same, and a frangible element connecting between said part and second dog and resisting movement therebetween until broken by said upward pull on the wire line.

31. An apparatus useful in well operations comprising a mandrel adapted to be connected as a part of a string of well conduit, a port through a side wall of the mandrel and connecting between the interior and exterior of the mandrel, a sleeve valve having a port in a wall thereof and movable in said mandrel to move said sleeve port into and out of fluid registration with said mandrel port, an

- O-ring seal carried by one of the mandrels and sleeve valve and providing a sliding seal with the other of the mandrels and sleeve valve to prevent fluid flow therebetween, said seal being positioned so that one of said ports moves thereacross upon movement of the sleeve valve, said one port moving across the seal having at least a terminal portion formed in the shape of a narrow groove extending in a direction transverse to the circumferential axis of said O-ring whereby as said port with said narrow groove terminal portion is moved past saidO-ring, any pressure difierential across said O-ring is equalized without the O-ring being protruded into said groove and the last mentioned port by said pressure ditferential.

32. An apparatus useful in well operations comprising a mandrel adapted to be connected as a part of a string of well conduit and having a passage extending through a side wall thereof connecting between the interior and exterior of the mandrel, first and second flow control valves carried by the mandrel in series with each other and with said passage to control flow therethrough, said first flow control valve being of the pressure charged type so as to control flow through the passage responsive to variations in a control pressure to which said first flow control valve is exposed, said second flow control valve including a part movable to open and close said passage to fluid flow therethrough, and a mechanism movable through said conduit by a connection with the earths surface and being engageable with said part to move it between passage opening and closing positions.

33. A tool adapted to be positioned in a well conduit means by a wire line comprising a first extensible and retractable dog carried by the tool and movable to extended position for engagement with an upwardly facing shoulder carried by the conduit means; a second extensible and retractable dog carried by the tool for movement to extended positioned for engagement with a downwardly facing shoulder carried by the conduit means upon upward movement of the tool after the tool has been lowered into the conduit means; and means releasably holding the first dog in retracted position while the tool is being lowered into the conduit means and movable to release said first dog for movement to extended position responsive to an upward pull on the tool while said second dog is engaged with said downwardly facing shoulder.

34. A tooladapted to be positioned in a well conduit means by a wire line comprising a first extensible and retractable dog carried by the tool and movable to extended position for engagement with said conduit means to limit downward movement of the tool through the conduit means; a second extensible and retractable dog carried by the tool for movement to an extended position for engagement with the conduit means to limit upward movement of the tool through the conduit means; and means releasably holding the first dog in retracted position while thetool is being lowered into the conduit means and movable to release said first dog for movement to extended position responsive to an upward pull on the tool while the second dog is in engagement with said conduit means.

References Cited in the file of this patent 'UNITED STATES PATENTS 2,305,250 Garrett Dec. 15, 1942 2,380,022 Burt July 10, 1945 2,634,689 Walton Apr. 14, 1953 

